Conventionally, there is developed a plasma generation apparatus using electromagnetic waves. For example, Japanese Unexamined Patent Application, Publication No. 2007-113570 discloses an ignition device employing a plasma generation apparatus that causes plasma discharge to occur by emitting microwaves to a combustion chamber in an internal combustion engine or the like before and/or after ignition of air fuel mixture. In the plasma generation apparatus, local plasma can be generated utilizing a discharge at an ignition plug, and can enhance this plasma using microwaves.
However, in the conventional plasma generation apparatus, there is a disadvantage that generation efficiency of the plasma is not sufficient in relation to usage power.